Visualizing relations with Prolog

relations.pl

/*
Prerequite: graphviz, prolog
Install (ubuntu): apt install graphviz swi-prolog

Usage:
  - launch `prolog` from the terminal in the same folder as this file
  - consult(relations).
  - tell('./relations.gv'), graph(relation),told.
  - halt.
  - dot -Tjpg relations.gv | display
*/

%Replace with your own relations
relation(a, b).
relation(a, c).

%You can leave this as is
graph(Fact2) :-
   format('digraph ~s {~n', [Fact2]),
   forall(call(Fact2, From, To), format(' ~s -> ~s;~n', [From, To])),
   format('}\n').

Following these instructions you should now be shown an image that looks like this:
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